This invention relates generally to thermoplastic components and more particularly bonding of such components by friction stir welding.
It is known in the prior art to construct composite materials using a thermoplastic polymer matrix with reinforcing fibers, hereinafter referred to as “thermoplastic composites”. These materials combine light weight and good strength. Typically, the reinforcing fibers are relatively short in length and are oriented randomly so that the component will have isotropic properties. Examples of turbine engine components which may be constructed from reinforced plastic include rotating fan blades, outlet guide vanes, reverser cascades, and various other static structures.
Thermoplastic composites can be molded to desired shapes or can be bonded through means such as heat welding. Unfortunately, the fluid flow that occurs during the welding process disturbs this intended orientation and therefore undesirably creates an area along the joint in which only the matrix carries any loads placed on the component.
Accordingly, there is a need for joining thermoplastic composites while maintaining their mechanical properties.